Munehito Yoshida

Prevalence of radiographic knee osteoarthritis and its association with knee pain in the elderly of Japanese population-based cohorts: The ROAD study

OBJECTIVE We investigated the prevalence of radiographic knee osteoarthritis (OA) and knee pain in the Japanese elderly using a large-scale population of a nationwide cohort study, Research on Osteoarthritis Against Disability (ROAD), and examined their association. METHODS From the baseline survey of the ROAD study, 2,282 participants > or =60 years (817 men and 1,465 women) living in urban, mountainous and seacoast communities were analyzed. The radiographic severity at both knees was determined by the Kellgren/Lawrence (KL) grading system. KL> or =2 and KL> or =3 knee OA were examined separately to assess osteophytosis and joint space narrowing (JSN). RESULTS The prevalence of KL> or =2 OA (47.0% and 70.2% in men and women, respectively) was much higher than that of previous studies in Caucasians, while that of KL> or =3 OA was not much different in men. Age, BMI, female sex and rural residency were risk factors for radiographic knee OA, knee pain and their combination. The prevalence of knee pain was age-dependent in women, but not in men. Knee pain was more strongly associated with KL> or =3 OA than with KL=2, and the association was higher in men than in women. Female sex was a strong risk factor even in the subgroup without radiographic knee OA (KL=0/1). CONCLUSION The present cross-sectional study revealed a high prevalence of radiographic knee OA in the Japanese elderly. Knee pain was strongly associated with JSN especially in men, while women tended to have knee pain even without radiographic OA.

Early complications of high-dose methylprednisolone sodium succinate treatment in the follow-up of acute cervical spinal cord injury.

Study Design A prospective, randomized, and double-blind study comparing high-dose methylprednisolone sodium succinate (MPSS) with placebo, in the treatment of patients with acute cervical spinal cord injury. Objectives To evaluate the complications of high-dose MPSS in patients with acute cervical spinal cord injury when administered within 8 hours of injury. Summary of Background Data High-dose therapy with MPSS has been demonstrated to improve the recovery of motor function in patients with acute cervical spinal cord injury. However, little is known about the follow-up complications. Methods Forty-six patients, 42 men and 4 women (mean age, 60.6 years; range, 18–84), were included in the study: 23 in the MPSS group and 23 in the placebo group. They were treated without surgery for spinal cord injury in the cervical spine, and were enrolled in the trial if a diagnosis had been made and treatment had begun within 8 hours. Complications of high-dose therapy with MPSS were compared with placebo treatment throughout the study period and up to 2 months after injury. Results The MPSS group had 13 patients (56.5%) with complications, whereas the placebo group had 8 (34.8%). The difference between the two groups was not statistically significant (P = 0.139). There were eight instances of pulmonary complication with MPSS (34.8%) and one instance (4.34%) with placebo (P = 0.009). There were four instances of gastrointestinal complication (17.4%) with MPSS and none with placebo (P = 0.036). Pulmonary (complications were more prevalent in patients aged more than 60 years (P = 0.029). Conclusion Aged patients with cervical spinal injury may be more likely to have pulmonary side effects (P = 0.029) after high-dose therapy with MPSS and thus deserve special care.

Hypertrophied ligamentum flavum in lumbar spinal canal stenosis : pathogenesis and morphologic and immunohistochemical observation

To investigate the pathogenesis of hypertrophy of the ligamentum flavum, 45 cases of lumbar canal stenosis were evaluated by computed tomography scan and pathologic and immunohistochemical studies. The ligamentum flavum along with the medial one-third of the superior facet was obtained an bloc to include the enthesis. Statistically significant differences in transverse area and thickness of the ligamentum flavum were evident compared to the control gourp (P<0.01). Pathogenesis of the hypertrophied ligamentum flavum was classified into three major groups: 1) fibrocartilage change due to proliferation of type II collagen, 2) ossification, and 3) calclum crystal depostion. It is stressed that marked proliferation of Type II collagen from the enthesis to the ligament side was revealed in the capsular portion of the hypertophied ligament.

Lumbar sagittal balance influences the clinical outcome after decompression and posterolateral spinal fusion for degenerative lumbar spondylolisthesis.

Study Design. This study was designed to assess both lumbar sagittal balance and clinical outcomes of decompression and posterolateral fusion for degenerative lumbar spondylolisthesis. As an index for the radiologic evaluation of sagittal alignment, the L1 axis S1 distance was used (i.e., the horizontal distance from the plumbline of the center in the L1 to the back corner of the S1). Objective. To determine whether lumbar sagittal balance affected the clinical outcome after posterolateral fusion. Summary of Background Data. Little is known about whether the sagittal vertical axis influences clinical outcomes in cases of degenerative lumbar spondylolisthesis. Methods. A retrospective review of 47 patients (15 men and 32 women), ranging in age from 41 to 79 years, was conducted. The mean follow-up period was 3.6 years. Relations among outcomes including the visual analog pain scale, recovery rate, L1 axis S1 distance, slippage, and lumbar lordosis were evaluated. Results. Recovery rates were 44% and 62% in patients whose preoperative L1 axis S1 distance, respectively, was more than 35 mm (Group A, n = 16) and less than 35 mm (Group B, n = 31) (P < 0.05). Follow-up assessment found a positive correlation between only lordosis and recovery rate. Severe low back pain and lower recovery rate were observed in patients with in situ fusion in Group A (n = 9), as compared with patients with reduced slippage in Group A (n = 7) and patients in Group B. Conclusions. Both preoperative L1 axis S1 distance and lordosis at follow-up assessment affected surgical outcome. Reduction of slippage may improve clinical outcomes of posterolateral fusion for degenerative lumbar spondylolisthesis with an L1 axis S1 distance more than 35 mm.

Expansive laminoplasty with reattachment of spinous process and extensor musculature for cervical myelopathy

Since 1986 we have performed expansive laminoplasty with reattachment of the spinous processes and extensor musculature in cases of cervical myelopathy to avoid the late postoperative complications of extensive laminectomy. The operative procedure and results are given in detail. Forty cases (24 men, 16 women) were followed for a mean of 28 months. Postoperative results were satisfactory, with no major complications according to the evaluation criteria of the japanese Orthopaedic Association. No instability or malalignment was seen on postoperative radiographs.

A comparative study of surgical approaches for cervical compressive myelopathy.

Since 1986, the authors have used anterior decompression and fusion to treat patients with one-or two-level lesions without spinal canal stenosis (Group A) and laminoplasty for patients with more than three-level lesions or spinal canal stenosis (Group P). The aim of this study was to compare surgical outcomes of anterior and posterior approaches for patients with cervical myelopathy because of spondylosis and disc herniation and to determine the cause of poor neurologic recovery after surgery. One hundred thirty-six patients were followed up for an average of 5.6 years. There were no significant differences in gender, preoperative neurologic deficits, axial symptoms, or duration of symptoms before surgery between the two groups. Mean recovery rates for disc herniations were 71.1% and 71.9% in Groups A and P, respectively. For spondylosis, mean recovery rates were 49.0% and 58.6% in Groups A and P, respectively. There were no differences in recovery rate for patients with either spinal disorder between Groups A and P. The neurologic recovery of patients with kyphotic spinal cord was inferior to that of patients with lordotic or straight spinal cord. It is possible that acquisition and maintenance of lordosis result in improvement of clinical outcomes after surgery for patients with myelopathy.

The use of cultured bone marrow cells in type I collagen gel and porous hydroxyapatite for posterolateral lumbar spine fusion.

Study Design. Posterolateral lumbar transverse process fusion was completed using the cultured bone marrow cells in type I collagen gel and porous hydroxyapatite. Objective. To compare the efficacy of cultured bone marrow cells with that of bone morphogenetic protein (BMP) as a graft alternative to autologous bone for posterolateral spine fusion. Summary of Background Data. The clinical application of BMP for spinal fusion may be limited by high dose and cost. Recently, mesenchymal stem cells have been studied in various fields because of their capability to differentiate into various cells, including those in the osteogenic lineage. Methods. Thirty adult rabbits were used. Each underwent single-level, bilateral, posterolateral intertransverse process fusions at L4–L5. The animals were divided into 4 groups, each according to the material implanted: (1) autologous bone (autograft, n = 9); (2) porous hydroxyapatite (HA) particles and type I collagen sheet with 100 &mgr;g rhBMP-2 (BMP-HA, n = 7); (3) bone marrow cells (1 × 106cells/mL, low-marrow-HA, n = 7); and (4) bone marrow cells (1 × 108cells/mL, high-marrow-HA, n = 7). Before implantation for groups 3 and 4, fresh bone marrow cells from the iliac crest of each animal were cultured in a standard medium for 2 weeks. For one additional week, the marrow cells were cultured in 10−8M dexamethasone, type I collagen gel, and HA. Animals were euthanized 6 weeks after surgery. Spinal fusions were evaluated by radiograph, manual palpation, and histology. Results. The fusion rates were 4 of 7 in the autograft group, 7 of 7 in the BMP-HA group, 0 of 7 in the low-marrow-HA group, and 5 of 7 in the high-marrow-HA group. The histology in the BMP-HA and high-marrow-HA groups showed that grafted HA fragments were connected with mature new bone. The pores of HA fragments were filled up with bone matrix. In the low-marrow-HA group, fibrous tissue was predominant in the grafted fragments. Conclusions. This study shows that the cultured bone marrow cells can act as a substitute for autograft or BMP in spine fusion. The current formulation may yield improved fusion success and better quality of fusion bone as compared to autograft.

Axial symptoms and cervical alignments after cervical anterior spinal fusion for patients with cervical myelopathy.

This retrospective clinical study was designed to examine the relation between cervical alignment and axial symptoms developing after cervical anterior spinal fusion. Sixty patients with myelopathy treated with cervical anterior spinal fusion were reviewed. For radiographic evaluation, lordosis, enlargement of the fused segments and neural foramen, radiographic union, and degeneration of adjacent segment were reviewed before or after surgery or both. Twenty-three patients had axial symptoms. Only local kyphosis and narrowing of the neural foramen at the fused segment were recognized more often in patients with axial symptoms than in those without such symptoms. No less than 2 mm and < or = 5 mm in enlargement of the anterior disc space immediately after surgery resulted in maintenance of cervical lordosis. These findings suggest that > or = 2 mm and < or = 5 mm in enlargement of anterior vertebral body height during operation results in prevention of axial symptoms.

Prevalence and distribution of intervertebral disc degeneration over the entire spine in a population-based cohort: the Wakayama Spine Study

OBJECTIVES The purposes of this study were to investigate the prevalence and distribution of intervertebral disc degeneration (DD) over the entire spine using magnetic resonance imaging (MRI), and to examine the factors and symptoms potentially associated with DD. DESIGN This study included 975 participants (324 men, mean age of 67.2 years; 651 women, mean age of 66.0 years) with an age range of 21-97 years in the Wakayama Spine Study. DD on MRI was classified into Pfirrmanns system (grades 4 and 5 indicating DD). We assessed the prevalence of DD at each level in the cervical, thoracic, and lumbar regions and the entire spine, and examined DD-associated factors and symptoms. RESULTS The prevalence of DD over the entire spine was 71% in men and 77% in women aged <50 years, and >90% in both men and women aged >50 years. The prevalence of an intervertebral space with DD was highest at C5/6 (men: 51.5%, women: 46%), T6/7 (men: 32.4%, women: 37.7%), and L4/5 (men: 69.1%, women: 75.8%). Age and obesity were associated with the presence of DD in all regions. Low back pain was associated with the presence of DD in the lumbar region. CONCLUSION The current study established the baseline data of DD over the entire spine in a large population of elderly individuals. These data provide the foundation for elucidating the causes and mechanisms of DD.

Does reconstruction of posterior ligamentous complex with extensor musculature decrease axial symptoms after cervical laminoplasty

Study Design. The authors retrospectively determined the prevalence of neck and shoulder symptoms (axial symptoms) after expansive laminoplasty with reattachment of spinous process and extensor musculature in patients with cervical myelopathy. Objectives. To determine the prevalence of both preoperative and postoperative axial symptoms of expansive laminoplasty when they occur after expansive laminoplasty. Summary of Background Data. Several clinical reports have noted that laminoplasty for cervical myelopathy produces positive clinical outcomes. However, recent reports have pointed out that complications from laminoplasty, such as axial symptoms, may be severe enough to interfere with daily activities. Methods. The authors used a modified spinous process–splitting laminoplasty, which involved reattaching the spinous process with extensor musculature after enlarging the spinal canal by use of the French window method. Postoperative axial symptoms were investigated in 173 of 214 patients (80.1%) who underwent expansive laminoplasty between January 1989 and December 1998. The patients included 121 men and 52 women, and their average age was 61.5 years. The presence or absence and grade of axial symptoms before and after laminoplasty were investigated. The severity and duration of complications were also recorded, along with differences between age, sex, spinal alignment, and cervical diseases. Results. Neck and/or shoulder stiffness worsened in 15% of the patients and declined in 21%. Neck pain worsened in 10% of the patients and improved in 11%. Neck and/or shoulder stiffness worse than moderate was recognized in 14.4% of the patients. Neck pain worse than moderate was recognized in 5% of the patients. In the 137 patients who had no axial pain before surgery, only 13 patients experienced such symptoms after surgery, and in most cases these symptoms were minimal. In only 1 case, significant postoperative neck pain arose de novo as a result of this surgery. In 88 patients who had no neck and/or shoulder stiffness before surgery, only 16 patients experienced such symptoms after surgery, and in most cases these were minimal. A similar pattern held true for each of the other grades of preoperative axial symptoms. The recovery rate score (Japanese Orthopedic Association) was 47.5 ± 32.3 in the patients whose axial symptoms were worse than moderate and 60 ± 28.9 in patients whose axial symptoms were less than mild. This difference was significant (P < 0.05). Conclusion. Laminoplasty is an appropriate operation for cervical spondylotic myelopathy and did not, in this study, seem to have any significant influence on the development or resolution of axial symptoms.